There is a substantial need in the microelectronics industry for high quality, photodefinable dielectric materials. In many applications, such as in multichip modules, the dielectric polymer is ideally tough, resistant to thermoxidation, adherent and has good insulating capability. An ideal material exhibits low moisture absorption, a low dielectric constant and a low coefficient of thermal expansion. The material should be capable of low temperature processing, simple photodefinability and preferably be applicable from solution.
Polyimides, the materials conventionally used, leave much to be desired. Polyimides typically require high curing temperatures on the order of 300.degree. C. and evolve water during curing. They have high moisture absorbance which makes their dielectric constant vary with humidity. Accordingly, there is a need for an improved material for making photodefinable layers.